Thanks to Curbana for making me aware of this 2012 doctoral thesis which I had not seen before, written by University of Colorado doctoral candidate in electrical engineering Olga Dmitriyeva titled “Mechanism of heat generation from loading gaseous hydrogen isotopes into palladium nanoparticles” which is an attempt to understand the underlying cause of the anomalous heat effect measured in palladium-deuterium reactions first made famous by Pons and Fleischmann in 1989.

Dmitriyeva states that her interest in this subject stemmed from the fact that there were claims by some researchers that the excess heat measured correlated with helium production (indicating a nuclear reaction) while other attempts were unsuccesful.

Without getting in to the details of the research, Dmitriyeva carried out which are described exhaustively in the thesis (see the link above), she concludes that the heat phenomenon can be explained as a result of an artefact caused by a chemical reaction.

Here is a summary from the introduction:

To prove the chemical nature of the observed phenomena I demonstrated that the reaction can be either exo- or endothermic based on the water isotope trapped in the material and the type of gas provided to the system. The H/D exchange was confirmed by RGA, NMR and FTIR analysis. I quantified the amount of energy that can be released due to the H/D exchange and proved that the heat generated during the experiments can be fully accounted for by this chemical reaction.

At the end of the dissertation in a section about future work, Dmitriyeva mentions the work that has been done in the field of nickel-hydrogen reactions and notes that her chemical reaction conclusion does not apply to nickel-hydrogen reactions. She writes:

[T]here is another large cluster of work that has been done with Ni and NiCu alloy materials and hydrogen, and for which H/D exchange
reaction does not provide an explanation. Hydrogen, as a reaction gas, does not satisfy the condition for the exothermic reaction described in Table 4. Hydrogen exposure would produce either no heat if the material is saturated with H2O, or the reaction would be endothermic if D2O 89 is trapped in the sample. I do not dismiss the chemical explanation to the excess heat observed in Ni-H systems, but the details of the reaction are unknown.

I am guessing that this will be considered a controversial study by many cold fusion enthusiasts, but I post it here because I think it’s relevant to the discussion, and the research seems to have been done in a thorough manner (I am not qualified to critique the experimental protocols used). I do find it interesting that Andrea Rossi, while giving credit to Pons and Fleischmann foropeningg a new field of study, seems to not to believe that their process was valid. He himself tried to replicate their effect without success in his early research, and recently made this comment:

What inspired me to begin, to be honest and sincere, has been the work of Prof Fleishmann and Prof Pons when it has been announced the first time. This is a merit they deserve, even if the electrolysis concept was, and still is, wrong. The electrolysis brings nowhere. Obviously, this is only my opinion and, as such, can be wrong.